The dark side of the Milky Way: revealed by pulsar measurements

Scientists have found the dark side of the Milky Way

The scientists associate the constant expansion of the Universe with mysterious dark energy. But there is an acceleration in galaxies, the stars experience it, and it can be with a combination of dark matter and the density of stars. For the first time, the scientists managed to obtain a direct measurement of the average acceleration that occurs in the Milky Way Galaxy.

The study was conducted by the specialists from the Rochester Institute of Technology and the University of Wisconsin-Milwaukee. They used pulsar data to measure the radial and vertical acceleration of stars inside and outside the galaxy.


As a result, they were able to calculate the density of the dark matter of the Milky Way using high-frequency measurements and a known amount of matter in the galaxy. First, they concluded that the galaxy is in a stable state. Overall, the analysis gave researchers the ability to measure more than just the tiny accelerations experienced by stars in the galaxy. But also to expand knowledge data on the nature of dark energy on a large scale.

The speed of stars traveling in the galaxy can reach several hundred kilometers per second. But speed changes occur and they are hardly noticeable. To identify it, the scientists relied on the ultra-precise ability to keep the time of the pulsars.

They are widespread throughout the galactic region and even in the halo. Astrophysicist Philip Chang noted that he and his colleagues relied on the unique properties of pulsars to measure small accelerations in the Galaxy, opening a new window of knowledge in galactic dynamics.


This knowledge, in turn, provides theoretical grounds for searching for dark matter, for calculating galactic equilibrium in the state of the galaxy. The Milky Way has its own characteristics. It has a turbulent history of galaxies and is still under its influence.

It is outraged by the influences of the outer galaxies such as the Large and Small Magellanic Clouds. The researchers believe that their results allow a wide range of calculations and measurements of accelerations using the additional radial velocity method.

Reference: “A measurement of the Galactic plane mass density from binary pulsar accelerations” by Sukanya Chakrabarti, Philip Chang, Michael T. Lam, Sarah J. Vigeland, Alice C. Quillen, accepted, Astrophyiscal Journal Letters. arXiv: 2010.04018